docs: def _get_rate(self, mag):
          """
          Calculate and return the annual occurrence rate for a specific bin.
  
          :param mag:
              Magnitude value corresponding to the center of the bin of interest.
          :returns:
              Float number, the annual occurrence rate for the :param mag value.
          """
          mag_lo = mag - self.bin_width / 2.0
          mag_hi = mag + self.bin_width / 2.0
  
          if mag >= self.min_mag and mag < self.char_mag - DELTA_CHAR / 2:
              # return rate according to exponential distribution
              return (10 ** (self.a_val - self.b_val * mag_lo)
                      - 10 ** (self.a_val - self.b_val * mag_hi))
          else:
              # return characteristic rate (distributed over the characteristic
              # range) for the given bin width
              return (self.char_rate / DELTA_CHAR) * self.bin_width